If you use a #2 filter to start then the next filter is the next grade.

If you use no filter, then find you need to go up or down a grade, what filter do you pick, and what is the exposure change?

(If you know the answer to that - or have worked it out - great. But this used to bug me... I didn't really know how far the next step or what exposure it would take.)

Bill has it right.

Also, when you use the #2 filter for an exposure, and then decide that a #2.5 filter would be better, you will be able to use an exposure time with the #2.5 filter that is either the same or very close to the same as the exposure time you used with the #2 filter.

It also helps to systemize your process - if you have a workflow that always deals with contrast filtration, you will be much less likely to forget to use the filtration when you mean to do so.

Matt

“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

If you use a #2 filter to start then the next filter is the next grade.

Pardon me if I misunderstand your meaning, but it seems you are suggesing that the filter # is equal to a contrast grade. There is no real correlation between a single VC filter and an ISO Range Number. Generally, the higher the filter #, then the higher the apparent contrast. But, it is possible for two filters to produce the same, or very near the same contrast i.e., ISO Range Number, given the particular paper, light source, and developer.

My thoughts were not to use a #2 filter 'specifically' or to rely on the grades being ANSI.

I just think it would be a good idea to use a filter (or filtration) instead of unfiltered so that you don't have to figure out the next step.

Good point.

I referred to using a #2 filter because most likely that will give contrast that is most similar to the unfiltered exposure, and therefore would fit well with the rest of the suggested procedure I was responding to.

But another filter or filter setting can also be made to work.

Matt

“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2